]> git.karo-electronics.de Git - karo-tx-linux.git/blob - drivers/iommu/s390-iommu.c
intel-hid: allocate correct amount of memory for private struct
[karo-tx-linux.git] / drivers / iommu / s390-iommu.c
1 /*
2  * IOMMU API for s390 PCI devices
3  *
4  * Copyright IBM Corp. 2015
5  * Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com>
6  */
7
8 #include <linux/pci.h>
9 #include <linux/iommu.h>
10 #include <linux/iommu-helper.h>
11 #include <linux/pci.h>
12 #include <linux/sizes.h>
13 #include <asm/pci_dma.h>
14
15 /*
16  * Physically contiguous memory regions can be mapped with 4 KiB alignment,
17  * we allow all page sizes that are an order of 4KiB (no special large page
18  * support so far).
19  */
20 #define S390_IOMMU_PGSIZES      (~0xFFFUL)
21
22 struct s390_domain {
23         struct iommu_domain     domain;
24         struct list_head        devices;
25         unsigned long           *dma_table;
26         spinlock_t              dma_table_lock;
27         spinlock_t              list_lock;
28 };
29
30 struct s390_domain_device {
31         struct list_head        list;
32         struct zpci_dev         *zdev;
33 };
34
35 static struct s390_domain *to_s390_domain(struct iommu_domain *dom)
36 {
37         return container_of(dom, struct s390_domain, domain);
38 }
39
40 static bool s390_iommu_capable(enum iommu_cap cap)
41 {
42         switch (cap) {
43         case IOMMU_CAP_CACHE_COHERENCY:
44                 return true;
45         case IOMMU_CAP_INTR_REMAP:
46                 return true;
47         default:
48                 return false;
49         }
50 }
51
52 static struct iommu_domain *s390_domain_alloc(unsigned domain_type)
53 {
54         struct s390_domain *s390_domain;
55
56         if (domain_type != IOMMU_DOMAIN_UNMANAGED)
57                 return NULL;
58
59         s390_domain = kzalloc(sizeof(*s390_domain), GFP_KERNEL);
60         if (!s390_domain)
61                 return NULL;
62
63         s390_domain->dma_table = dma_alloc_cpu_table();
64         if (!s390_domain->dma_table) {
65                 kfree(s390_domain);
66                 return NULL;
67         }
68
69         spin_lock_init(&s390_domain->dma_table_lock);
70         spin_lock_init(&s390_domain->list_lock);
71         INIT_LIST_HEAD(&s390_domain->devices);
72
73         return &s390_domain->domain;
74 }
75
76 static void s390_domain_free(struct iommu_domain *domain)
77 {
78         struct s390_domain *s390_domain = to_s390_domain(domain);
79
80         dma_cleanup_tables(s390_domain->dma_table);
81         kfree(s390_domain);
82 }
83
84 static int s390_iommu_attach_device(struct iommu_domain *domain,
85                                     struct device *dev)
86 {
87         struct s390_domain *s390_domain = to_s390_domain(domain);
88         struct zpci_dev *zdev = to_pci_dev(dev)->sysdata;
89         struct s390_domain_device *domain_device;
90         unsigned long flags;
91         int rc;
92
93         if (!zdev)
94                 return -ENODEV;
95
96         domain_device = kzalloc(sizeof(*domain_device), GFP_KERNEL);
97         if (!domain_device)
98                 return -ENOMEM;
99
100         if (zdev->dma_table)
101                 zpci_dma_exit_device(zdev);
102
103         zdev->dma_table = s390_domain->dma_table;
104         rc = zpci_register_ioat(zdev, 0, zdev->start_dma + PAGE_OFFSET,
105                                 zdev->start_dma + zdev->iommu_size - 1,
106                                 (u64) zdev->dma_table);
107         if (rc)
108                 goto out_restore;
109
110         spin_lock_irqsave(&s390_domain->list_lock, flags);
111         /* First device defines the DMA range limits */
112         if (list_empty(&s390_domain->devices)) {
113                 domain->geometry.aperture_start = zdev->start_dma;
114                 domain->geometry.aperture_end = zdev->end_dma;
115                 domain->geometry.force_aperture = true;
116         /* Allow only devices with identical DMA range limits */
117         } else if (domain->geometry.aperture_start != zdev->start_dma ||
118                    domain->geometry.aperture_end != zdev->end_dma) {
119                 rc = -EINVAL;
120                 spin_unlock_irqrestore(&s390_domain->list_lock, flags);
121                 goto out_restore;
122         }
123         domain_device->zdev = zdev;
124         zdev->s390_domain = s390_domain;
125         list_add(&domain_device->list, &s390_domain->devices);
126         spin_unlock_irqrestore(&s390_domain->list_lock, flags);
127
128         return 0;
129
130 out_restore:
131         zpci_dma_init_device(zdev);
132         kfree(domain_device);
133
134         return rc;
135 }
136
137 static void s390_iommu_detach_device(struct iommu_domain *domain,
138                                      struct device *dev)
139 {
140         struct s390_domain *s390_domain = to_s390_domain(domain);
141         struct zpci_dev *zdev = to_pci_dev(dev)->sysdata;
142         struct s390_domain_device *domain_device, *tmp;
143         unsigned long flags;
144         int found = 0;
145
146         if (!zdev)
147                 return;
148
149         spin_lock_irqsave(&s390_domain->list_lock, flags);
150         list_for_each_entry_safe(domain_device, tmp, &s390_domain->devices,
151                                  list) {
152                 if (domain_device->zdev == zdev) {
153                         list_del(&domain_device->list);
154                         kfree(domain_device);
155                         found = 1;
156                         break;
157                 }
158         }
159         spin_unlock_irqrestore(&s390_domain->list_lock, flags);
160
161         if (found) {
162                 zdev->s390_domain = NULL;
163                 zpci_unregister_ioat(zdev, 0);
164                 zpci_dma_init_device(zdev);
165         }
166 }
167
168 static int s390_iommu_add_device(struct device *dev)
169 {
170         struct iommu_group *group;
171         int rc;
172
173         group = iommu_group_get(dev);
174         if (!group) {
175                 group = iommu_group_alloc();
176                 if (IS_ERR(group))
177                         return PTR_ERR(group);
178         }
179
180         rc = iommu_group_add_device(group, dev);
181         iommu_group_put(group);
182
183         return rc;
184 }
185
186 static void s390_iommu_remove_device(struct device *dev)
187 {
188         struct zpci_dev *zdev = to_pci_dev(dev)->sysdata;
189         struct iommu_domain *domain;
190
191         /*
192          * This is a workaround for a scenario where the IOMMU API common code
193          * "forgets" to call the detach_dev callback: After binding a device
194          * to vfio-pci and completing the VFIO_SET_IOMMU ioctl (which triggers
195          * the attach_dev), removing the device via
196          * "echo 1 > /sys/bus/pci/devices/.../remove" won't trigger detach_dev,
197          * only remove_device will be called via the BUS_NOTIFY_REMOVED_DEVICE
198          * notifier.
199          *
200          * So let's call detach_dev from here if it hasn't been called before.
201          */
202         if (zdev && zdev->s390_domain) {
203                 domain = iommu_get_domain_for_dev(dev);
204                 if (domain)
205                         s390_iommu_detach_device(domain, dev);
206         }
207
208         iommu_group_remove_device(dev);
209 }
210
211 static int s390_iommu_update_trans(struct s390_domain *s390_domain,
212                                    unsigned long pa, dma_addr_t dma_addr,
213                                    size_t size, int flags)
214 {
215         struct s390_domain_device *domain_device;
216         u8 *page_addr = (u8 *) (pa & PAGE_MASK);
217         dma_addr_t start_dma_addr = dma_addr;
218         unsigned long irq_flags, nr_pages, i;
219         unsigned long *entry;
220         int rc = 0;
221
222         if (dma_addr < s390_domain->domain.geometry.aperture_start ||
223             dma_addr + size > s390_domain->domain.geometry.aperture_end)
224                 return -EINVAL;
225
226         nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
227         if (!nr_pages)
228                 return 0;
229
230         spin_lock_irqsave(&s390_domain->dma_table_lock, irq_flags);
231         for (i = 0; i < nr_pages; i++) {
232                 entry = dma_walk_cpu_trans(s390_domain->dma_table, dma_addr);
233                 if (!entry) {
234                         rc = -ENOMEM;
235                         goto undo_cpu_trans;
236                 }
237                 dma_update_cpu_trans(entry, page_addr, flags);
238                 page_addr += PAGE_SIZE;
239                 dma_addr += PAGE_SIZE;
240         }
241
242         spin_lock(&s390_domain->list_lock);
243         list_for_each_entry(domain_device, &s390_domain->devices, list) {
244                 rc = zpci_refresh_trans((u64) domain_device->zdev->fh << 32,
245                                         start_dma_addr, nr_pages * PAGE_SIZE);
246                 if (rc)
247                         break;
248         }
249         spin_unlock(&s390_domain->list_lock);
250
251 undo_cpu_trans:
252         if (rc && ((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID)) {
253                 flags = ZPCI_PTE_INVALID;
254                 while (i-- > 0) {
255                         page_addr -= PAGE_SIZE;
256                         dma_addr -= PAGE_SIZE;
257                         entry = dma_walk_cpu_trans(s390_domain->dma_table,
258                                                    dma_addr);
259                         if (!entry)
260                                 break;
261                         dma_update_cpu_trans(entry, page_addr, flags);
262                 }
263         }
264         spin_unlock_irqrestore(&s390_domain->dma_table_lock, irq_flags);
265
266         return rc;
267 }
268
269 static int s390_iommu_map(struct iommu_domain *domain, unsigned long iova,
270                           phys_addr_t paddr, size_t size, int prot)
271 {
272         struct s390_domain *s390_domain = to_s390_domain(domain);
273         int flags = ZPCI_PTE_VALID, rc = 0;
274
275         if (!(prot & IOMMU_READ))
276                 return -EINVAL;
277
278         if (!(prot & IOMMU_WRITE))
279                 flags |= ZPCI_TABLE_PROTECTED;
280
281         rc = s390_iommu_update_trans(s390_domain, (unsigned long) paddr, iova,
282                                      size, flags);
283
284         return rc;
285 }
286
287 static phys_addr_t s390_iommu_iova_to_phys(struct iommu_domain *domain,
288                                            dma_addr_t iova)
289 {
290         struct s390_domain *s390_domain = to_s390_domain(domain);
291         unsigned long *sto, *pto, *rto, flags;
292         unsigned int rtx, sx, px;
293         phys_addr_t phys = 0;
294
295         if (iova < domain->geometry.aperture_start ||
296             iova > domain->geometry.aperture_end)
297                 return 0;
298
299         rtx = calc_rtx(iova);
300         sx = calc_sx(iova);
301         px = calc_px(iova);
302         rto = s390_domain->dma_table;
303
304         spin_lock_irqsave(&s390_domain->dma_table_lock, flags);
305         if (rto && reg_entry_isvalid(rto[rtx])) {
306                 sto = get_rt_sto(rto[rtx]);
307                 if (sto && reg_entry_isvalid(sto[sx])) {
308                         pto = get_st_pto(sto[sx]);
309                         if (pto && pt_entry_isvalid(pto[px]))
310                                 phys = pto[px] & ZPCI_PTE_ADDR_MASK;
311                 }
312         }
313         spin_unlock_irqrestore(&s390_domain->dma_table_lock, flags);
314
315         return phys;
316 }
317
318 static size_t s390_iommu_unmap(struct iommu_domain *domain,
319                                unsigned long iova, size_t size)
320 {
321         struct s390_domain *s390_domain = to_s390_domain(domain);
322         int flags = ZPCI_PTE_INVALID;
323         phys_addr_t paddr;
324         int rc;
325
326         paddr = s390_iommu_iova_to_phys(domain, iova);
327         if (!paddr)
328                 return 0;
329
330         rc = s390_iommu_update_trans(s390_domain, (unsigned long) paddr, iova,
331                                      size, flags);
332         if (rc)
333                 return 0;
334
335         return size;
336 }
337
338 static struct iommu_ops s390_iommu_ops = {
339         .capable = s390_iommu_capable,
340         .domain_alloc = s390_domain_alloc,
341         .domain_free = s390_domain_free,
342         .attach_dev = s390_iommu_attach_device,
343         .detach_dev = s390_iommu_detach_device,
344         .map = s390_iommu_map,
345         .unmap = s390_iommu_unmap,
346         .iova_to_phys = s390_iommu_iova_to_phys,
347         .add_device = s390_iommu_add_device,
348         .remove_device = s390_iommu_remove_device,
349         .pgsize_bitmap = S390_IOMMU_PGSIZES,
350 };
351
352 static int __init s390_iommu_init(void)
353 {
354         return bus_set_iommu(&pci_bus_type, &s390_iommu_ops);
355 }
356 subsys_initcall(s390_iommu_init);